JPH07189299A - Hydraulic device of work machine - Google Patents

Abstract

PURPOSE:To make it possible to carry out reproduction operation in conformity with switching over of the operating direction of an actuator in simple and small-sized structure. CONSTITUTION:Logic valves 6 to 9 are provided between a hydraulic pump 2 and a hydraulic cylinder 1 where a throttle 26 is installed to a joint drain pipeline 26. When non-reproduction mode (regular mode) is set, a pair of logic valves are opened in conformity with the operating direction of an operation lever 4 where the operation direction of the hydraulic cylinder 1 is switched over. When reproduction operation mode is set by extending the hydraulic cylinder 1, if the pressure in-flow port 29 of the logic valve 8 is lower than the pressure in a flow-out port 30, the logic valve 8 is opened, thereby allowing the hydraulic cylinder 1 to perform the reproduction operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to civil engineering such as hydraulic excavators,
The present invention relates to a hydraulic system for a working machine for construction work.

[0002]

2. Description of the Related Art For example, in a hydraulic excavator, a hydraulic cylinder for driving an arm, a boom and a bucket,
Various actuators such as a turning hydraulic motor and an operating lever for an operator to operate these actuators are provided, and pressure oil is supplied from a hydraulic pump to each actuator according to the operation of the operating lever to operate the actuator. I am trying to let you. In this case, a directional switching valve for switching the operating direction of the actuator is interposed between the actuator and the hydraulic pump, and the directional switching valve is switched according to the operating direction of the operating lever to allow the pressure oil to flow into the actuator.・
The outflow direction is switched.

Further, in a hydraulic system for a work machine of this type, the flow rate of pressure oil to the actuator is usually controlled in accordance with the operating amount of the operating lever so that an operating speed corresponding to the operating amount of the operating lever is obtained. Therefore, a relatively large operating speed can be obtained by increasing the operation amount of the operating lever.However, for example, when not working, it is possible to drive the actuator to the standby position or the like more quickly. Often required.

For this reason, it is known that pressure oil discharged from the outflow chamber of the actuator is recirculated to the inflow chamber to perform so-called regeneration. The operating speed can be increased rapidly.

In this case, in the conventional hydraulic device using the directional control valve, in order to perform the above-mentioned regeneration,
The hydraulic circuit for the regeneration must be formed inside the directional control valve or provided separately from the directional control valve.

However, when the hydraulic circuit for regeneration is formed inside the directional control valve, the spool valve of the directional control valve becomes complicated and expensive, and
Since a large amount of pressure oil flows through the directional control valve, the configuration of the directional control valve becomes large. When the size of the directional control valve is increased in this way, a hydraulic circuit of relatively high pressure and high capacity for driving the spool valve is also required, which disadvantageously increases the size of the hydraulic device. Further, when the hydraulic circuit for regeneration is formed inside the directional control valve, the regeneration as described above is always performed, and it becomes difficult to obtain the operating speed according to the operation amount of the operation lever. There was an inconvenience.

Further, when the hydraulic circuit for regeneration is provided separately from the directional control valve, the directional control valve itself can be prevented from becoming larger and more complicated, and the directional control valve equipped with the circuit for regeneration can be avoided. Although it is possible to perform regeneration as necessary by using such as, etc., the switching valve becomes large in size because a large flow rate of pressure oil is flown through the switching valve itself. When the size of the switching valve is increased, a relatively high pressure and high capacity hydraulic circuit is required to drive the switching valve, which causes an inconvenience of increasing the size of the hydraulic device.

[0008]

SUMMARY OF THE INVENTION In view of the above background, the present invention provides a hydraulic device for a working machine capable of switching the operating direction of an actuator and performing a regenerating operation as necessary with a simple and compact structure. The purpose is to

[0009]

In order to achieve such an object, the present invention comprises a hydraulic pump, an actuator using the hydraulic pump as a drive source, and an operating lever for setting the operating direction of the actuator. By supplying pressure oil from the hydraulic pump to one of a pair of oil chambers formed in the actuator and discharging the pressure oil from the other oil chamber in correspondence with the operating direction set by the operation lever, In a hydraulic device of a working machine operated by the actuator, the hydraulic pump is provided in a pair of actuator side pipelines respectively connecting a pump side pipeline derived from a discharge port of the hydraulic pump and a pair of oil chambers of the actuator. A pair of openable and closable inflow side logic valves and each actuation between each inflow side logic valve and the oil chamber of the corresponding actuator. A pair of discharge side logic valves respectively provided in a pair of discharge pipelines led out from the eater side pipeline, and a discharge provided in a merged discharge pipeline formed by joining the pair of discharge pipelines A side throttle, a mode setting means for selectively setting the operation mode of the actuator between a regeneration operation mode and a non-regeneration operation mode, and when the operation mode set by the mode setting means is a non-regeneration operation mode, One of the pair of inflow side and outflow side logic valves corresponding to the operation direction set by the operation lever is opened to open a set of inflow side and outflow side logic valves, and the other set of inflow side and outflow side logic is opened. The valve is closed, and when the operation mode is the regeneration mode, a set of inflow side and outflow side logic valves corresponding to the operation direction set by the operation lever is opened. In addition, at least when the actuator is actuated in one actuating direction, the pressure of the other outflow side logic valve on the side of the merged discharge conduit is higher than the pressure on the inflow chamber side of the actuator, and the other outflow side logic valve And a logic valve drive means for closing the other inflow side logic valve.

Further, the other outflow-side logic valve that is opened in the regeneration mode opens / shuts off the pilot oil chamber that is in communication with the inflow port portion on the actuator side via the first throttle passage. And the second throttle passage led out from the outflow port portion of the outflow side logic valve on the side of the merged discharge pipeline is communicated with the pilot oil chamber from the outflow port side to the second outflow port side. The logic valve drive means is configured to open when pilot pressure oil flows through the throttle passage and the first throttle passage, and close when pilot pressure oil flows in the opposite direction. When the mode is the non-regeneration operation mode, the pilot oil chamber of the other outflow side logic valve is made to correspond to the operation direction of the actuator while blocking the second throttle passage. And means for opening and blocking Te, when the operation mode is the playback mode, characterized in that it comprises a means for communicating the pilot oil chamber of the other of the outlet-side logic valve to said second throttle passage.

Further, the logic valve driving means includes a three-position switching valve connected to the pilot oil chamber of the other outflow-side logic valve and the second throttle passage, and the three-position switching valve is the above-mentioned three-position switching valve. A position that shuts off both the pilot oil chamber of the other outflow side logic valve and the second throttle passage, and a position that opens the pilot oil chamber of the other outflow side logic valve and shuts off the second throttle passage. , The other outflow side logic valve is configured to be switchable between a pilot oil chamber communicating with the second throttle passage, and the logic valve drive means sets the three-position switching valve to the operating direction of the actuator. It is characterized in that the other outflow side logic valve is opened and closed by switching and driving in correspondence with the operation mode.

Further, each logic valve other than the other outflow side logic valve is configured to open and close by opening / closing a pilot oil chamber which is communicated with an inflow port through a throttle passage. The means includes a two-position switching valve that is switchable between an open position and a shut-off position that are respectively connected to the pilot oil chambers of the logic valves other than the other outflow-side logic valve, and the two-position switching valve is the actuator. It is characterized in that each of the logic valves except the other outflow side logic valve can be opened and closed by switching and driving in accordance with the operation direction of.

Alternatively, each of the logic valves other than the other outflow side logic valve is configured to open and close by opening and closing the pilot oil chamber, and the logic valve drive means is configured to operate in one of the operating directions of the actuator. Corresponding to the first pilot line connected to the pilot oil chamber of the pair of inflow side and outflow side logic valves to be opened, and the other to be opened corresponding to the other operating direction of the actuator. A second pilot line connected to the pilot oil chambers of the pair of inflow-side and outflow-side logic valves; a neutral position for shutting off both the first and second pilot lines;
A three-position switching valve that is switchably connected to both pilot conduits between a pair of open positions that open only one of the pilot conduits, a pilot oil chamber of the other outflow side logic valve, and the first A pilot oil chamber of the other outflow side logic valve and a two-position switching valve connected to the second throttle passage so as to be freely switchable between a position where the second throttle passage is blocked and a position where the throttle passage is in communication with each other; Each of the logic valves is opened and closed by switching the position switching valve in correspondence with the operating direction of the actuator and switching the two-position switching valve in accordance with the operating mode of the actuator.

Further, the discharge throttle provided in the merged discharge pipe line is constituted by a variable throttle, and is detected by the pressure detecting means for detecting the pressure of the actuator on the inflow chamber side of the pressure oil, and the pressure detecting means. A throttle control means for increasing the throttle area of the discharge throttle when the pressure becomes equal to or higher than a predetermined pressure.

Further, the discharge throttle provided in the merged discharge pipe line is constituted by a variable throttle, and is detected by the pressure detection means for detecting the pressure of the pressure oil on the inflow chamber side of the actuator, and the pressure detection means. It is characterized by further comprising throttle control means for increasing the throttle area of the discharge throttle when the pressure becomes equal to or lower than a predetermined pressure.

[0016]

According to the present invention, in the non-regeneration operation mode, that is, in the normal state, the logic valve drive means operates the inflow side and outflow side logic valves corresponding to the operating direction of the actuator set by the operation lever. By opening the valve and closing the other set of the inflow side and outflow side logic valves, pressure oil is supplied from the hydraulic pump to the inflow side oil chamber of the actuator through the opened inflow side logic valve. At the same time, the pressure oil is discharged from the oil chamber on the outflow side of the actuator via the outflow side logic valve opened, whereby the actuator operates in the operation direction set by the operation lever. And at this time,
Since the pressure oil discharged from the actuator is discharged through the discharge throttle of the merge discharge pipe line, the pressure on the upstream side of the discharge throttle becomes high. Therefore, in the regeneration mode, the pressure of the other outflow side logic valve, which is normally closed, on the side of the merged discharge line is higher than the pressure on the side of the inflow chamber of the actuator, and the other outflow side logic valve. When the valve is opened by the logic valve drive means, the pressure oil discharged from the actuator is returned to the inflow chamber of the actuator from the upstream side of the discharge throttle of the merged discharge pipe line through the other outlet side variable throttle as described above. As a result, the regeneration operation of the actuator is performed. Therefore, it is possible to switch the operation direction of the actuator and perform the regeneration operation by simply opening and closing all the pair of inflow side and outflow side logic valves. Further, each of the logic valves does not require a large operating force for driving them as compared with the directional switching valve that has been conventionally used, and a relatively small logic valve is used to achieve high pressure and high capacity. Since it is possible to cope with this, it is possible to make the configuration of each of the logic valves and the logic valve drive means small, and therefore, a configuration for performing switching of the operating direction of the actuator and regeneration operation is possible. It becomes possible to make it small.

Each of the logic valves is generally configured to open and close by opening and closing a pilot oil chamber that communicates with an inflow port portion through a throttle passage (first throttle passage). However, when the second throttle passage is further led out from the outflow port portion and the second throttle passage is communicated with the pilot oil chamber, the first throttle passage and the second throttle passage are connected to each other. If the throttle area etc. are set appropriately, the valve will open when the pilot pressure oil flows from the outflow port side through the second throttle passage and the first throttle passage, and the pilot pressure oil will reverse. It is possible to close the valve when it flows in the direction. Therefore, the other outflow-side logic valve is configured as described above, and when opening and closing the other outflow-side logic valve, the other outflow-side logic valve is normally closed (non-regeneration operation mode) while blocking the second throttle passage. The pilot oil chamber of the valve is opened / closed in accordance with the operating direction of the actuator, and in the regeneration mode, the pilot oil chamber of the other outflow side logic valve is made to communicate with the second throttle passage. By doing so, normally, the outflow side logic valve is easily opened / closed in accordance with the mere opening / closing of the pilot oil chamber of the other outflow side logic valve. Further, in the regeneration mode, when the pressure on the side of the merged discharge conduit of the other outflow side logic valve is higher than the pressure on the side of the inflow chamber of the actuator, the pressure is applied from the outflow port side of the outflow side logic valve. Since the pilot pressure oil flows through the second throttle passage and the first throttle passage, the outflow side logic valve is opened, whereby the pressure oil discharged from the actuator is passed through the other outflow side logic valve. And recirculates to the oil chamber on the inflow side of the actuator to perform regeneration operation. Then, at this time, when the pressure of the other outflow side logic valve on the side of the merged discharge conduit becomes lower than the pressure on the side of the inflow chamber of the actuator, the pilot pressure oil of the outflow side logic valve flows in the opposite direction to the above. Therefore, it is possible to avoid a situation in which the outflow side logic valve is closed and therefore the pressure oil in the inflow chamber of the actuator is discharged through the other outflow side logic valve.

In this case, in order to drive the other outflow side logic valve as described above, the three positions connected to the pilot oil chamber of the other outflow side logic valve and the second throttle passage. It is easily performed by switching the switching valve according to the operating direction and operating mode of the actuator.
Further, since the 3-position switching valve can use a small pressure oil with a small flow rate and does not require a large operating force, the switching drive can be electrically performed. .

Further, each logic valve other than the other outflow side logic valve is configured to be opened and closed by simply opening and closing the pilot oil chamber,
By simply switching and driving the two-position switching valve connected to the pilot oil chamber of each logic valve, each logic valve can be easily opened and closed in accordance with the operating direction of the actuator. As these two-position switching valves, small ones can be used as with the three-position switching valve, and the switching drive thereof can be electrically performed.

Alternatively, when the three-position switching valve connected to the first and second pilot lines and the two-position switching valve connected to the pilot oil chamber of the other outflow side logic valve are used, the actuator Switching of the operating direction is easily performed only by switching and driving the three-position switching valve,
Further, it is possible to easily switch the operation mode of the actuator between the non-regeneration operation mode and the regeneration operation mode simply by switching and driving the two-position switching valve. And
The three-position switching valve and the two-position switching valve can be small in size, and the number of parts for driving each logic valve is small, so that the structure of the logic valve drive means can be made smaller. It becomes possible to make it simple.

Further, the discharge throttle provided in the merged discharge pipeline is constituted by a variable throttle, and when the pressure on the inflow chamber side of the pressure oil of the actuator becomes equal to or higher than a predetermined pressure, the discharge throttle is controlled by the throttle control means. By increasing the throttle area of, when the load of the actuator is large,
Since the throttle area of the discharge throttle is increased, the outflow resistance of the pressure oil discharged from the actuator is reduced, and the smooth operation of the actuator is enabled.

Further, the discharge throttle provided in the merged discharge pipeline is constituted by a variable throttle, and when the pressure of the pressure oil of the actuator on the side of the inflow chamber becomes a predetermined pressure or less, the discharge is controlled by the throttle control means. By increasing the throttle area of the throttle, especially in the regeneration mode, when the load of the actuator is small, the throttle area of the discharge throttle increases, so the pressure of the pressure oil on the discharge side decreases and the inflow chamber of the actuator decreases. The flow rate of the pressure oil that flows back to the cylinder is reduced, which prevents a situation in which the operating speed of the actuator is extremely increased.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a system configuration diagram of the apparatus of this embodiment, FIG. 2 is a block configuration diagram of a main part of FIG. 1, and FIGS.
5 is a flow chart for explaining the operation of the apparatus of FIG. 1, and FIG. 5 is a flow chart for explaining the operation of the apparatus of FIG.

Referring to FIG. 1, the apparatus of the present embodiment is mounted on, for example, a hydraulic excavator, 1 is a hydraulic cylinder (actuator) for driving an arm of the hydraulic excavator, and 2 is a hydraulic cylinder 1. A hydraulic pump as a drive source, 3 is an operating device having an operating lever 4 for an operator to operate the hydraulic cylinder 1, and 5 is a controller constituted by an electronic circuit including a microcomputer (not shown), 6, 7 , 8 and 9 are logic valves for switching the operating direction of the hydraulic cylinder 1 and performing regenerating operation,
Reference numerals 10, 11, and 12 are 2-position electromagnetic switching valves for driving the logic valves 6, 7, 9 respectively, 13 is a 3-position electromagnetic switching valve for driving the logic valve 8, and 14 is pressure oil to the hydraulic cylinder 1. The electromagnetic proportional flow rate control valve for controlling the flow rate of the valve, 15 is a pressure compensation type electromagnetic proportional unload valve for controlling the pressure on the inflow side of the electromagnetic proportional flow rate control valve 14, and 16 is the suction / discharge of the hydraulic pump 2. It is an oil tank containing pressure oil.

The hydraulic pump 2 is of a variable displacement type whose capacity can be controlled via a regulator 17, and is driven by an engine of a hydraulic excavator (not shown) to suck and discharge oil in the oil tank 16.

In the pump-side pipe line 18 led out from the discharge port of the hydraulic pump 2, a check valve 19 is sequentially provided from the upstream side.
And a pair of actuator side pipelines 20a, 20b branched from the pump side pipeline 18 on the downstream side of the electromagnetic proportional flow rate control valve 14 are respectively provided on the bottom side of the hydraulic cylinder 1. It is connected to the oil chamber 21 and the rod-side oil chamber 22. Each actuator side conduit 2
The inflow side logic valves 6 and 7 and the check valves 23 and 24 are sequentially installed in the 0a and 20b from the electromagnetic proportional flow control valve 14 side. In addition, discharge lines 25a and 25b are led out from the actuator side pipes 20a and 20b, respectively, on the downstream side of the check valves 23 and 24, and the discharge pipes 25a and 25a are discharged.
Outflow side logic valves 8 and 9 are interposed in 25b, respectively. The discharge pipe lines 25a and 25b are joined to the merge discharge pipe line 26 on the downstream side of the outflow side logic valves 8 and 9 to reach the oil tank 16. Then, in the merged discharge pipe line 26, a discharge side throttle 26 having a variable throttle area constituted by an electromagnetic proportional valve is provided.
a is provided.

Further, from the pump side pipe line 18 between the hydraulic pump 2 and the check valve 19, a pipe line 27 for retrieving the surplus oil of the pressure oil discharged from the hydraulic pump 2 to the oil tank 16 is led out. In the pipe 27, the electromagnetic proportional unload valve 15
And a throttle 28 is provided on the downstream side of the electromagnetic proportional unload valve 15.

The respective logic valves 6 to 9 have the same basic structure. For example, the logic valve 6 has an inflow port 29 and an outflow port which are connected to the upstream side and the downstream side of the actuator side pipeline 20a, respectively. A sleeve 31 having a port 30 at its tip, a poppet valve 32 slidable in the sleeve 31, a pilot oil chamber 33 provided at the rear of the sleeve 31, a pilot oil chamber 33 and an inflow port 29 are connected to each other. The poppet valve 32 includes a throttle passage 34a formed inside the poppet valve 32. The poppet valve 32 comes into contact with a valve seat 35 formed at the tip portion of the sleeve 31 when it is slid toward the tip end side of the poppet valve 32. And the outflow port 30 are closed to close the pipe 20a, and when slid to the rear end side, the inflow port 29 and the outflow port 30 are communicated by separating from the valve seat 35. And so as to open the conduit 20a. The poppet valve 32 is urged by the spring 36 housed in the pilot oil chamber 33 toward the valve seat 35 side, that is, toward the valve closing side. Such a configuration is basically the same for the other logic valves 7 to 9.

In the logic valves 6 to 9, when the pilot oil chamber 33 is opened, a part of the pressure oil flowing into the inflow port 29 passes through the throttle passage 34 and the pilot oil chamber 3 is opened.
3, the pressure on the inflow port 33 side becomes higher than the pressure on the pilot oil chamber 33, so that the poppet valve 32 slides to the side away from the valve seat 35 against the urging force of the spring 36. As a result, the inflow port 29 and the outflow port 30 communicate with each other to open the valve. When the pilot oil chamber 33 is shut off (closed), the poppet valve 32 is brought into pressure contact with the valve seat 35 by the urging force of the spring 36 to close the valve.
At this time, the inlet port 33 side and the pilot oil chamber 33
Since the pressure difference between the poppet valve 32 and the area of the poppet valve 32 on the pilot oil chamber 33 side is larger than the area of the inflow port 33 side, a force that pushes the poppet valve 32 against the valve seat 35 side acts, which ensures the reliability. Is kept closed.

In such logic valves 6 to 9,
In general, it is possible to handle high pressure and high capacity with a compact structure, leakage of pressure oil is extremely small, and further, in order to open / close the logic valves 6 to 9, simply opening / closing the pilot oil chamber 33. Since it is good, it does not require a large operating force.

The configuration and operation of each logic valve 6 to 9 as described above are basically common to each logic valve 6 to 9, but for the outflow side logic valve 8 from the outflow port 30 thereof. The throttle passage 3 is provided on the outer side of the sleeve 31.
4b (second throttle passage) is led out. The logic valve 8 operates as follows when the pilot oil chamber 33 communicates with the throttle passage 34b.

That is, the outflow port 30 of the logic valve 8
When the pressure on the side is higher than the pressure on the side of the inflow port 29 (the pressure of the bottom side oil chamber 21 of the hydraulic cylinder 1), the pressure oil flows through the throttle passage 34b, the pilot oil chamber 33 and the throttle passage 34a to the side of the inflow port 29. To the outflow port 30 at this time
The side pressure becomes sufficiently higher than the pressure in the pilot oil chamber 33, the poppet valve 32 slides to the valve opening side, and the logic valve 8 opens. On the contrary, when the pressure on the inflow port 29 side of the logic valve 8 becomes higher than the pressure on the outflow port 30 side, the pressure oil flows to the outflow port 30 side via the throttle passage 34a, the pilot oil chamber 33 and the throttle passage 34b. At this time, the pressure on the outflow port 30 side becomes sufficiently lower than the pressure on the pilot oil chamber 33, the poppet valve 32 slides toward the valve closing side, and the logic valve 8 closes. This kind of operation
This is performed by appropriately setting the throttle areas of the throttle passages 34a and 34b and the elastic force of the spring 36 of the logic valve 8. The operation of the logic valve 8 in the state where the pilot oil chamber 33 is shut off from the throttle passage 34b is as described above.

Each logic valve 6 except the logic valve 8
Pilot lines 37, 38, 39 reaching the oil tank 16 are connected to the pilot oil chambers 33 of Nos. 7 and 9, and the two-position electromagnetic switching valves 10, 11 are respectively connected to these pilot lines 37, 38, 39. , 12 are interposed. Each electromagnetic switching valve 10 to 12 is a two-position switching valve that is switchable between a closed position to close each pilot conduit 37 to 39 and an open position to open each pilot conduit 37 to 39, and each logic valve 6, 7, at the closed position. 9 shuts off the pilot oil chamber 33 and opens each logic valve 6,
The 7 and 9 pilot oil chambers 33 are opened to the oil tank 16 side.

Further, the pilot oil chamber 33 of the logic valve 8
Pilot line 40 and the throttle passage 3 derived from
The three-position electromagnetic switching valve 13 is interposed between 4b and the conduit 40a communicating with the oil tank 16. The electromagnetic switching valve 34b includes a pilot conduit 40 and the throttle passage 34b.
Position A (neutral position) where both are separated from each other to be blocked from the oil tank 16 side, and the pilot pipe 40 is opened to the oil tank 16 side and the throttle passage 34b is blocked B.
It is freely switchable between a position and a C position where the pilot pipe line 40 and the throttle passage 34b are communicated with each other while blocking the oil tank 16 side.

The operating lever 4 of the operating device 3 is, for example, swingable in the front-back direction, so that the operator can move the hydraulic cylinder 1
When it is desired to extend, the operation lever 4 is swung forward, and when the hydraulic cylinder 1 is desired to be shortened, the operation lever 4 is swung backward. The operation device 3 includes an operation amount detector 41 that detects an operation direction and an operation amount of the operation lever 4 with a potentiometer or the like. The operation amount detector 41 operates the operation lever 4 as shown in FIG. 3, for example. A detection signal (electrical signal) having a polarity corresponding to the direction and having a level proportional to the operation amount of the operation lever 4 (hereinafter, referred to as lever operation amount) is output. The operating lever 4
A dead zone (see FIG. 3) is provided near the neutral position, and the level of the detection signal output from the manipulated variable detector 41 is 0 level in the dead zone.

The electromagnetic proportional flow control valve 14 is provided in the pump side conduit 18 between the hydraulic pump 2 and the check valve 19.
A pressure sensor 42 for detecting the pressure P ₁ on the inflow side of the electromagnetic proportional flow control valve 14 is provided in the pump side pipe line 18 on the downstream side of the electromagnetic proportional flow control valve 14.
A pressure sensor 43 that detects ₂ is provided. Also,
The pipe line 27 provided with the electromagnetic proportional unload valve 15 and the like
The pressure P ₃ between the unload valve 15 and the throttle 28.
A pressure sensor 44 for detecting In this case, since the diaphragm 28 is constant, the pressure sensor 44
The pressure P ₃ detected by means of the pressure P ₃ depends on the flow rate of the surplus oil flowing through the pipe line 27.

Further, in FIG. 1, reference numeral 45 is a mode setting device (mode setting device) for the operator to selectively set the operation mode of the hydraulic cylinder 1 to a regeneration operation mode and a non-regeneration operation mode (normal mode) described later. Means).

Referring to FIG. 2, the controller 5
As a functional configuration, the pressure detected by the pressure sensor 44
Pressure P of surplus oil₃According to the capacity of the hydraulic pump 2,
Then, the discharge flow rate of the hydraulic pump 2 is adjusted via the regulator 17.
Via a pump control unit 45 that controls the
Pressure P on the inflow side of the electromagnetic proportional flow control valve 14 detected by
₁The electric current detected through the pressure sensor 43 while monitoring
Pressure P on the outflow side of the magnetic proportional flow control valve 14₂According to electromagnetic
Differential pressure control unit 4 for controlling the set pressure of the proportional unload valve 15.
6 and the detection amount output from the operation amount detector 41 of the operation device 3.
Operation lever that can be grasped by the polarity of the output signal (see Fig. 3)
4 operation direction and operation set by the mode setter 45
Drive control of each of the electromagnetic switching valves 10 to 13 according to the mode
From the controlled logic valve control unit 47 and the manipulated variable detector 41
Lever operation grasped by the level of the output detection signal
The opening area of the electromagnetic proportional flow control valve 14 can be adjusted according to the work amount.
The flow rate control unit 48 for controlling and the pressure sensor 43 (pressure detection
Pressure on the inflow chamber side of the hydraulic cylinder 1 detected by
Power P₂The throttle area of the discharge side throttle 26a according to
A diaphragm control unit (diaphragm control means) 49 for
Here, the logic valve control unit 4 corresponds to the configuration of the present invention.
7 is a logic valve drive hand together with the electromagnetic switching valves 10 to 13.
It constitutes the stage 50.

Next, the operation of the apparatus of this embodiment will be described.

First, the case where the operation mode set by the mode setting device 45 is the non-reproduction operation mode (normal mode) will be described.

With reference to FIGS. 1, 2 and 5, in the apparatus of this embodiment, when the hydraulic cylinder 1 is extended, for example, an operator operates the hydraulic pump 2 and operates the operating lever 4. Swing forward. At this time, the operating lever 4
When it swings beyond the dead zone (see FIG. 3), the detection signal of the operating device 3 has a level proportional to the lever operation amount and has a polarity (negative level in this embodiment) corresponding to the operation direction. It is output from the manipulated variable detector 41 to the controller 5. Then, the logic valve control unit 47 of the controller 5
Indicates that the operation lever 4 has been swung forward due to the polarity (J <0 in FIG. 5) of the detection signal output from the operation amount detector 41, that is, the extension operation of the hydraulic cylinder 1 is required. It is understood that the solenoids of the electromagnetic switching valves 10 and 12 of the electromagnetic switching valves 10 to 13 are energized to drive the electromagnetic switching valves 10 and 12 to the open position.

As a result, the pilot oil chambers 33 of the logic valves 6 and 9 of the logic valves 6 to 9 are opened to the oil tank 16 side through the pilot pipe lines 37 and 39, respectively, and the logic valves 6 and 9 are opened. Open the valve. At this time, in the non-regeneration operation mode, the electromagnetic switching valve 11 is held in the closed position, and the electromagnetic switching valve 13 is held in the A position (neutral position). Therefore, in the logic valve 7, the pilot oil chamber 33 is shut off and held closed, and in the logic valve 8, the pilot oil chamber 33 and the throttle passage 34b are separated from each other. In this state, the valve is shut off and the valve is held closed as described above.

In parallel with the opening of the logic valves 6 and 9, the amount of pressure oil flowing through the electromagnetic proportional flow control valve 14, that is, to the bottom side oil chamber 21 which is the inflow chamber of the hydraulic cylinder 1 is changed. The inflow amount of pressure oil is controlled to an amount corresponding to the lever operation amount.

In this flow rate control, the controller 5
The differential pressure control unit 46 of the electromagnetic proportional flow control valve 14 detects the pressure P ₂ on the outflow side of the electromagnetic proportional flow control valve 14 detected by the pressure sensor 43, that is, the load pressure of the hydraulic cylinder 1. The pressure value obtained by adding the set differential pressure to the pressure P ₂ detected by the pressure sensor 43 is set to the electromagnetic proportional unload valve 15 so that the pressure P ₁ is increased by a preset set differential pressure. Indicate as pressure. As a result, the differential pressure (P ₂ −P ₁ ) between the upstream side and the downstream side of the electromagnetic proportional flow control valve 14 becomes equal to the hydraulic cylinder 1
A constant set differential pressure is maintained regardless of the load pressure of.

Further, in parallel with such operation, the flow rate control unit 48 of the controller 5 grasps the lever operation amount based on the level of the detection signal output from the operation amount detector 41, and is proportional to the lever operation amount. A command signal having a level is applied to the electromagnetic proportional flow control valve 14. At this time, the electromagnetic proportional flow rate control valve 14 opens with the level of the command signal given from the controller 5, that is, the opening area proportional to the lever operation amount.

As a result, the pressure oil discharged from the hydraulic pump 2 is transferred to the pump side pipe line 18 and the actuator side pipe line 2.
0a to the bottom side oil chamber 21 of the hydraulic cylinder 1 and is discharged from the rod side oil chamber 22 of the hydraulic cylinder 1 via the actuator side conduit 20b, the discharge conduit 25b, and the merge discharge conduit 26. Are collected in the oil tank 16 and the hydraulic cylinder 1 extends. Then, at this time, the differential pressure between the inflow side and the outflow side of the electromagnetic proportional flow control valve 14 (P ₂
-P ₁ ) is maintained at a constant set differential pressure, the flow rate of the pressure oil passing through the electromagnetic proportional flow control valve 14, that is,
The amount of pressure oil supplied to the hydraulic cylinder 1 is proportional to the opening area of the electromagnetic proportional flow control valve 14 regardless of the load pressure of the hydraulic cylinder 1, and the opening area of the electromagnetic proportional flow control valve 14 is a lever. Since it is proportional to the operation amount, the amount of pressure oil supplied to the hydraulic cylinder 1 is proportional to the lever operation amount. Therefore, the hydraulic cylinder 1 is supplied with pressure oil at a flow rate proportional to the lever operation amount, regardless of the magnitude or fluctuation of the load, and the hydraulic cylinder 1 expands at an operating speed corresponding to the lever operation amount. Will be done. At this time, the throttle area of the discharge side throttle 26a of the merged discharge pipeline 26 is controlled by the throttle control unit 49 of the controller 5 to, for example, a preset throttle area.

The above operation is similarly performed when the operation lever 4 is swung backward to shorten the hydraulic cylinder 1. In this case, the logic valve control section 47 of the controller 5 causes the electromagnetic switching. The solenoid of the valve 13 on the B position side is energized to switch the electromagnetic switching valve 13 to the B position, and the solenoid of the electromagnetic switching valve 11 is energized to switch the electromagnetic switching valve 11 to the open position. As a result, the pilot oil chamber 33 of the logic valves 7 and 8 is opened to the oil tank 16 side, and the logic valves 7 and 8 are opened as described above.

When the operating lever 4 is held in the neutral position including the dead zone, the electromagnetic switching valves 10 to 12 are used.
Are both held in the closed position, and the electromagnetic switching valve 13
Is also held at the A position, the logic valves 6 to 9 are held closed, and the electromagnetic proportional flow control valve 14 is also held closed, whereby both oil chambers 21 and 22 of the hydraulic cylinder 1 are closed. And is held in a stopped state. Further, during the operation as described above, the pump control unit 4 of the controller 5
5, the pressure P ₃ detected by the pressure sensor 44, the conduit 27 to grasp the flow rate of the hydraulic fluid (excess oil) flowing through the hydraulic pump as shown in FIG. 4, for example according to the pressure P ₃ 2 The capacity (discharging flow rate) is controlled between the maximum capacity and the minimum capacity. That is, as the flow rate of the excess oil flowing through the conduit 27 is large, since the pressure P ₃ increases due to the diaphragm 28, the pump control unit 45 of the controller 5 is enough the pressure P ₃ increases, the hydraulic pump in proportion to The capacity of 2 is reduced through the regulator 17. This allows
The flow rate of surplus oil is reduced, so that the hydraulic cylinder 1 can be operated at the discharge flow rate of the hydraulic pump 2 that is necessary for the operation of the hydraulic cylinder 1.

The displacement control of the hydraulic pump 2 may be controlled in proportion to the lever operation amount.

Next, the operation when the operation mode set by the mode setter 45 is the reproduction operation mode will be described.

In the hydraulic system of this embodiment, when the regeneration operation mode is set by the mode setter 45 in the extension operation of the hydraulic cylinder 1 as described above, the regeneration operation is performed together with the extension operation of the hydraulic cylinder 1 as follows. Done.

That is, when the operating lever 4 is operated to the front side in order to extend the hydraulic cylinder 1 in the regeneration operation mode, the logic valves 6 and 9 are opened, as in the case of the non-regeneration operation mode described above, and Electromagnetic proportional flow control valve 1
4, the flow rate control according to the lever operation amount and the capacity control of the hydraulic pump 2 are performed.

On the other hand, at this time, the logic valve control unit 47 of the controller 5 energizes the solenoid on the C position side of the 3-position electromagnetic switching valve 13 to switch the electromagnetic switching valve 13 to the C position. As a result, the pilot oil chamber 33 of the logic valve 8 is connected to the throttle passage 34b via the pilot conduit 40 and the electromagnetic switching valve 13 in a state of being blocked from the oil tank 16 side.

At this time, the pressure oil discharged from the rod side oil chamber 22 which is the outflow chamber of the hydraulic cylinder 1 through the logic valve 9 is throttled by the discharge side throttle 26a of the merge discharge line 26. When the operating lever 4 is operated relatively large forward with the load of the hydraulic cylinder 1 being relatively small, the pressure on the outflow port 30 side of the logic valve 8 is greater than the pressure on the inflow port 29 side, that is, the load pressure of the hydraulic cylinder 1. Will also be higher. Therefore, from the outlet port 30 side of the logic valve 8, the throttle passage 34b, the pilot conduit 40,
The pilot pressure oil flows to the inflow port 29 side of the logic valve 8 through the pilot oil chamber 33 and the throttle passage 34a, and as a result, the logic valve 8 opens as described above. Then, when the logic valve 8 is opened in this way, the logic valve 9 moves from the rod-side oil chamber 22 which is the outflow chamber of the hydraulic cylinder 1.
The pressure oil discharged through the flow path flows back to the bottom side oil chamber 21 which is the inflow chamber of the hydraulic cylinder 1 via the logic valve 9 from the upstream side of the discharge side throttle 26a of the merged discharge pipe line 26, whereby The regeneration operation of the hydraulic cylinder 1 is performed, and the hydraulic cylinder 1 extends at a high operating speed.

Further, during such a regeneration operation,
The throttle control unit 49 of the controller 5 uses the pressure sensor 43.
On the inflow chamber (bottom side oil chamber 21) side of the hydraulic cylinder 1.
Pressure P ₂Is being monitored and the detected pressure P₂Clear
Below the specified pressure set as the lower limit pressure
Then, the throttle area of the discharge side throttle 26a is increased. to this
As a result, the pressure on the outflow port 30 side of the logic valve 8 decreases.
Therefore, the oil flows back to the bottom side oil chamber 21 of the hydraulic cylinder 1.
The flow rate of pressure oil decreases and the extension operation speed of the hydraulic cylinder 1
An extremely large situation is avoided. The pressure P
₂If the pressure returns above the lower limit pressure above,
The throttle control unit 49 of the controller 5 controls the discharge side throttle 26a.
Return the original area.

Further, when the pressure P ₂ detected by the pressure sensor 43 becomes equal to or higher than a predetermined pressure set as the upper limit pressure in advance, the throttle control section 49 of the controller 5 increases the throttle area of the discharge side throttle 26a. This allows
The outflow resistance of the pressure oil of the hydraulic cylinder 1 is reduced to reduce the load on the hydraulic cylinder 1, and the smooth regeneration operation of the hydraulic cylinder 1 is performed. When the pressure P ₂ returns to a pressure equal to or lower than the upper limit pressure, the throttle control unit 49 of the controller 5 restores the throttle area of the discharge side throttle 26a to the original.

When the load on the hydraulic cylinder 1 increases during the above-described regeneration operation, the pressure in the bottom side oil chamber 21 of the hydraulic cylinder 1 increases and the pressure on the inflow port 29 side of the logic valve 8 increases. May become higher than the pressure on the outflow port 30 side, but in this case, the logic valve 8
The pilot pressure oil flows from the inflow port 29 side of the logic valve 8 to the outflow port 29 side of the logic valve 8 through the throttle passage 34a, the pilot oil chamber 33, the pilot conduit 40, and the throttle passage 34b. Therefore, as described above, the situation where the logic valve 8 is closed and the pressure oil in the bottom side oil chamber 21 of the hydraulic cylinder 1 is discharged via the logic valve 8 is avoided.

In the shortening operation of the hydraulic cylinder 1,
Even in the regeneration operation mode, the same operation as in the non-regeneration operation mode described above is performed.

As described above, in the hydraulic system according to the present embodiment, the logic valves 6 to 9 capable of handling high pressure and high capacity with a compact structure are used, and basically, each logic valve 6 is used.
The opening / closing of the hydraulic cylinders 1 can be switched and the regenerating operation can be performed only by controlling the opening / closing of the hydraulic cylinders 1 to 9, and the opening / closing of the logic valves 6 to 9 is extremely simple using the electromagnetic switching valves 10 to 13. In addition, since the electromagnetic switching valves 10 to 13 are small in size and can sufficiently open and close the logic valves 6 to 9, switching of the operating direction of the hydraulic cylinder 1 and regeneration operation can be simplified. It can be easily performed with a small configuration.

In this embodiment, the opening and closing of the logic valve 8 during the regeneration operation is performed by using the throttle passage 34b or the like. However, the pressure on the inflow port 29 side and the outflow port 30 side of the logic valve 8 are set. The pressure may be detected, and the opening / closing control of the logic valve 8 at the time of the regeneration operation may be performed according to the pressures as in the present embodiment.

Further, in this embodiment, the discharge side throttle 2
Control of the diaphragm area 6a has been to perform in accordance with only the pressure P _2, it may be controlled in response to the further lever operation amount, and the like.

Further, in the present embodiment, the regeneration operation is performed only when the hydraulic cylinder 1 is extended, but it is also possible to perform the regeneration operation when the hydraulic cylinder 1 is shortened. Of course, it is also possible to perform only the regeneration operation. In this case, a throttle passage and a three-position electromagnetic switching valve may be provided corresponding to the logic valve 9 like the logic valve 8.

In this embodiment, the operator sets the operating mode by the mode setter 45. However, the controller automatically sets the operating mode according to the operating state of the hydraulic cylinder 1. It is also possible.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 6 is a system configuration diagram of the apparatus of this embodiment. In the following description, the same components as those in the above-described embodiment are designated by the same reference numerals, and detailed description will be omitted.

The hydraulic system of the present embodiment has the same basic configuration as the system of FIG. 1, and is different from the system of FIG. 1 only in the configuration of the logic valve drive means 50 for opening and closing the logic valves 6-9. The other structure is the same as that of the apparatus of FIG.

In the apparatus of this embodiment, the logic valve drive means 50 joins the conduits 51 and 52 of the logic valves 6 to 9 derived from the pilot oil chambers 33 of the logic valves 6 and 9, respectively. Pilot line 53
Pilot pipe 56 formed by merging pipe lines 54 and 55 derived from the pilot oil chamber 33 of the logic valves 7 and 8, respectively.
And these pilot lines 53, 56 and the oil tank 16
And a two-position electromagnetic switching valve 58 interposed between the pipe passage 55a led out from the pilot oil chamber 33 of the logic valve 8 and the throttle passage 34b. It has and. In this case, 3-position solenoid switching valve 5
7 is an A position that shuts off both of the pilot conduits 53 and 56, and opens the pilot conduit 53 to the oil tank 16 side,
Further, it is possible to switch between a B position where the pilot conduit 56 is blocked and a C position where the pilot conduit 53 is blocked and the pilot conduit 56 is opened to the oil tank 16 side. Further, the two-position electromagnetic switching valve 58 is switchable between a shut-off position that shuts off the pilot oil chamber 33 of the logic valve 8 and the throttle passage 34b and a communication position that connects the two. Further, the conduits 51, 52, 54 and 55 are provided with these conduits 5 at the A position (neutral position) of the electromagnetic switching valve 57.
Check valves 59 to 62 for preventing pressure oil from flowing to 1, 52, 54, 55 are provided.

In such an apparatus, the mode setter 45
When the operation mode set by is the non-regeneration operation mode, for example, when the hydraulic cylinder 1 is extended, the controller 5 energizes the solenoid on the B position side of the electromagnetic switching valve 57 to set the electromagnetic switching valve 57 to the B position. Switch to. As a result, only the pilot line 53 is provided in the oil tank 16
Side, that is, the pilot oil chamber 33 of the logic valves 6 and 9 is opened, and the logic valves 6 and 9 are opened. In parallel with this, the flow rate control in the electromagnetic proportional flow rate control valve 14 and the hydraulic pump 2 are performed in the same manner as in the above-described embodiment.
Capacity control is performed. At this time, the electromagnetic switching valve 58 is held at the shutoff position.

As a result, the hydraulic cylinder 1 extends at the operating speed corresponding to the lever operation amount. This operation is performed in the same manner by switching the electromagnetic switching valve 57 to the C position when the hydraulic cylinder 1 is shortened.

On the other hand, when the operation mode set by the mode setter 45 is the non-regeneration operation mode, when the hydraulic cylinder 1 is extended, the controller 5 causes the electromagnetic switching valve 57 to move to the B position in the same manner as in the above case. In addition to being switched and driven, the electromagnetic switching valve 58 is switched and driven by the controller 5 to the communication position. As a result, the pilot oil chamber 33 of the logic valve 8 is shut off from the oil tank 16 side by the electromagnetic switching valve 57, and at the same time the electromagnetic switching valve 5 is closed.
8 communicates with the throttle passage 34b, whereby the regeneration operation of the hydraulic cylinder 1 is performed in exactly the same manner as the above-mentioned embodiment.

In the device of this embodiment, not only the same effects as those of the device of the above-described embodiment are obtained, but also the structure for opening and closing the logic valves 6 to 9 becomes simpler, and the parts are The number of points is also reduced, and a more compact structure can be achieved.

In the embodiments described above, the driving of the hydraulic cylinder of the hydraulic excavator has been described as an example, but the present invention is not limited to this, and an actuator such as a hydraulic motor of the hydraulic excavator, other civil engineering, and construction. Needless to say, the present invention can be applied to a work machine.

[0072]

As is apparent from the above description, according to the present invention, an actuator using a plurality of logic valves capable of handling high pressure and high capacity with a compact structure and not requiring a large operating force. By configuring a hydraulic device for driving the actuator, and performing switching of the operating direction of the actuator and regeneration operation by controlling the opening and closing of each logic valve, the operating direction of the actuator can be simplified and compact. It is possible to accurately perform the switching of and the regeneration operation as needed. Further, since the opening / closing drive of each logic valve can be performed with a small configuration using an electromagnetic switching valve or the like, the overall configuration of the hydraulic device for performing switching of the operating direction of the actuator and regeneration operation can be made compact. It can be simple.

A throttle passage led from the outflow port portion of the outflow side logic valve that opens to return the pressure oil discharged from the outflow side oil chamber of the actuator to the inflow chamber side oil chamber during the regeneration operation. By communicating with the pilot oil chamber, when the pressure on the outflow port side of the outflow side logic valve is higher than the pressure on the inflow port side, the outflow side logic valve can be easily opened to regenerate the actuator. In addition, when the pressure on the outflow port side of the outflow side logic valve becomes lower than the pressure on the inflow port side, the outflow side logic valve automatically closes and the inflow of the actuator is performed. It is possible to avoid the situation where the pressure oil that has flowed into the oil chamber on the side is discharged, and it is possible to perform an accurate regeneration operation of the actuator, and
The outflow side logic valve can be opened and closed accurately with an extremely simple structure.

In this case, when the operating direction of the actuator is switched, the pilot oil chamber of the outflow side logic valve is opened or shut off, and the communication of the outflow side logic valve to the throttle passage of the pilot oil chamber is performed during the regeneration operation. By using the three-position switching valve, the opening / closing drive of the outflow side logic valve in switching the operating direction of the actuator and switching the operating mode can be easily performed with an extremely simple structure, and The three-position switching valve can be configured by using a small electromagnetic switching valve or the like. Therefore, the structure for opening / closing driving the outflow side logic valve can be simplified and downsized.

Furthermore, for each logic valve except the above-mentioned outflow side logic valve, the two-position switching valve is used to open and shut off the pilot oil chamber so that these logic valves correspond to the operating direction of the actuator. Can be opened and closed very easily, and the two-position switching valve is
Since it can be configured using a small electromagnetic switching valve or the like, the configuration for opening and closing each logic valve can be simplified and miniaturized.

Alternatively, the common 3-position switching valve collectively performs the opening / closing driving of each logic valve for switching the operating direction of the actuator, and the pilot oil chamber of the outflow side logic valve that opens / closes for the regenerating operation. By connecting and disconnecting the throttle passage with the two-position switching valve, the structure for opening and closing each logic valve can be simplified, and the number of parts is small and the size is small. Can be one.

Further, the discharge throttle provided in the merged discharge pipeline is constituted by a variable throttle, and when the pressure of the pressure oil of the actuator on the inflow chamber side becomes equal to or higher than a predetermined pressure, the throttle area of the discharge throttle is increased. When the load of the actuator is large, it is possible to reduce the outflow resistance of the pressure oil discharged from the actuator and to smoothly operate the actuator.

Further, when the pressure of the pressure oil on the side of the inflow chamber of the actuator becomes equal to or lower than a predetermined pressure, by increasing the throttle area of the discharge throttle, particularly in the regeneration mode, when the load of the actuator is small, the actuator is reduced. It is possible to reduce the flow rate of the pressure oil that flows back into the inflow chamber, and avoid a situation where the operating speed of the actuator becomes extremely high.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of an example of a hydraulic device for a working machine according to the present invention.

FIG. 2 is a block configuration diagram of a main part of FIG.

FIG. 3 is an explanatory view for explaining the operation of the apparatus of FIG.

FIG. 4 is an explanatory view for explaining the operation of the apparatus of FIG.

5 is a flow chart for explaining the operation of the apparatus of FIG.

FIG. 6 is a system configuration diagram of another example of the hydraulic device for a working machine according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Hydraulic cylinder (actuator), 2 ... Hydraulic pump, 4 ... Operation lever, 6-9 ... Logic valve, 10-1
3, 57, 58 ... Switching valve, 18 ... Pump side pipe line, 20
a, 20b ... Actuator side conduit, 25a, 25b ...
Discharge pipe line, 26 ... Combined discharge pipe line, 26a ... Discharge side throttle,
34a ... 1st throttle passage, 34b ... 2nd throttle passage, 4
3 ... Pressure detecting means, 45 ... Mode setting device (mode setting means), 49 ... Throttle control section, 50 ... Logic valve driving means.

Claims (7)

[Claims] 1. A hydraulic pump, an actuator using the hydraulic pump as a drive source, and an operating lever for setting an operating direction of the actuator, wherein the operating direction is set by the operating lever. A hydraulic system for a working machine, wherein hydraulic fluid is supplied from the hydraulic pump to one of a pair of oil chambers formed in the actuator and discharged from the other hydraulic chamber, thereby operating the actuator. A pair of open / close inflow side logic valves respectively provided in a pair of actuator side lines connecting the pump side line led out from the discharge port of the actuator and the pair of oil chambers of the actuator, and each inflow side logic valve. It is connected to a pair of discharge pipes which are respectively led out from the actuator side pipes between the valve and the corresponding oil chamber of the actuator. A pair of openable and closable outflow-side logic valves, a discharge-side throttle provided in a merged discharge conduit formed by merging the pair of discharge conduits, and an operation mode of the actuator that is not the regeneration operation mode. Mode setting means for selectively setting the regeneration operation mode, and the operation of the pair of inflow side and outflow side logic valves when the operation mode set by the mode setting means is a non-regeneration operation mode When one set of inflow side and outflow side logic valves corresponding to the operation direction set by the lever is opened and the other set of inflow side and outflow side logic valves are closed, and the operation mode is the regeneration mode. , Opening a pair of inflow side and outflow side logic valves corresponding to the operating direction set by the operating lever, and operating at least one of the actuators. The other outflow side logic valve is opened in a state where the pressure on the side of the merged discharge line of the other outflow side logic valve is higher than the pressure on the inflow chamber side of the actuator, and the other outflow side logic valve is opened. A hydraulic device for a working machine, comprising: a logic valve drive means for closing the logic valve. 2. The other outflow-side logic valve that is opened in the regeneration mode opens and shuts off a pilot oil chamber that communicates with an inflow port portion on the actuator side through a first throttle passage. And the second throttle passage led out from the outflow port portion of the outflow side logic valve on the side of the merged discharge pipe line is communicated with the pilot oil chamber from the outflow port portion side to the second side.
Is configured to open when the pilot pressure oil flows through the throttle passage and the first throttle passage, and close when the pilot pressure oil flows in the opposite direction. A means for opening and shutting off the pilot oil chamber of the other outflow side logic valve corresponding to the operating direction of the actuator while shutting off the second throttle passage when the operating mode is the non-regenerative operating mode; The hydraulic device for a work machine according to claim 1, further comprising: a unit that connects the pilot oil chamber of the other outflow side logic valve to the second throttle passage when the operation mode is the regeneration mode. 3. The logic valve drive means comprises a three-position switching valve connected to the pilot oil chamber of the other outflow-side logic valve and the second throttle passage, and the three-position switching valve comprises:
A position that shuts off both the pilot oil chamber of the other outflow side logic valve and the second throttle passage, and a position that opens the pilot oil chamber of the other outflow side logic valve and shuts off the second throttle passage And a position where the pilot oil chamber of the other outflow side logic valve communicates with the second throttle passage, the logic valve driving means operates the three-position switching valve to operate the actuator. 3. The hydraulic device for a working machine according to claim 2, wherein the other outflow side logic valve is opened and closed by switching and driving in correspondence with the direction and the operation mode. 4. Each logic valve other than the other outflow side logic valve is configured to open and close by opening and closing a pilot oil chamber that communicates with its inflow port via a throttle passage. The means includes a two-position switching valve that is switchable between an open position and a shut-off position that are respectively connected to the pilot oil chambers of the logic valves other than the other outflow-side logic valve, and the two-position switching valve is the actuator. 4. The hydraulic device for a working machine according to claim 3, wherein each of the logic valves except the other outflow side logic valve is opened and closed by switching and driving in correspondence with the operation direction of. 5. Each logic valve except the other outflow side logic valve is configured to open and close by opening and shutting off its pilot oil chamber, and the logic valve drive means,
A first pilot line connected to the pilot oil chamber of the pair of inflow side and outflow side logic valves to be opened corresponding to one operation direction of the actuator; and the other operation direction of the actuator. A second pilot line connected to the pilot oil chambers of the other set of inflow-side and outflow-side logic valves to be opened, and a neutral position and a first position for shutting off both the first and second pilot lines. A three-position switching valve connected to both pilot lines so as to be switchable between a pair of open positions that open only one of the first and second pilot lines, and pilot oil for the other outflow side logic valve. A pilot oil chamber of the other outflow-side logic valve and a two-position switching valve connected to the second throttle passage so as to be switchable between a position where the chamber and the second throttle passage are cut off and a position where they communicate with each other. Equipped with the above 3 positions 3. The logic valves are opened and closed by switching the switching valve in correspondence with the operating direction of the actuator and switching the two-position switching valve in accordance with the operating mode of the actuator. Hydraulic equipment for the work machine described. 6. The discharge throttle provided in the merged discharge pipeline is composed of a variable throttle, and pressure detection means for detecting the pressure of the actuator on the inflow chamber side of the pressure oil, and the pressure detection means detect the pressure. 2. A hydraulic device for a working machine according to claim 1, further comprising: throttle control means for increasing the throttle area of the discharge throttle when the pressure exceeds a predetermined pressure. 7. The discharge throttle provided in the merged discharge pipeline is constituted by a variable throttle, and pressure detection means for detecting the pressure of the pressure oil on the inflow chamber side of the actuator, and the pressure detection means detect the pressure. 2. The hydraulic system for a working machine according to claim 1, further comprising throttle control means for increasing the throttle area of the discharge throttle when the pressure becomes equal to or lower than a predetermined pressure.